090 WilLOSOPHICAt TRANSACTIONS. [anNO I769. 



like one piece finely polished. It was curiously supported, and so light in pro- 

 portion to its magnitude, as to be easily managed and directed by one hand. 

 The anterior part of the speculum is subtended by an iron arch, of 4. an inch 

 thick, in the middle of which, in the place of the burning focus, it was perforated 

 into a ring, supporting from both sides an iron fork, to receive the body to be 

 examined. Four of Mr. Ehrard's mirrors of this kind had the following di- 

 mensions : 



jyjo Perimeter. Dlam. or ordinate. Depth or abscissa. Dist. of the focus. 



'-' ,• Ft. Inci ;■' Ft. Inc. 



gr rf 1 29 4i>Jij iJib. . . 9 7. 



2 21 n^udvlit. . .6 8. 



3 16 4 5/wjl.;*'w 



4 13 2-J- 4 2. 



The effect of these mirrors, Dr. W. says, in burning, calcining, melting, 

 vitrifying, far exceeds any thing of the kind ever known. The hardest stones 

 hardly resisted a few seconds; metals were quickly perforated; vegetables in the 

 twinkling of an eye were burnt to a cinder and vitrified, and bones of animals 

 the same; of which several instances as usual are recorded. One experiment in 

 particular is, that if 2 of these mirrors be placed directly opposite to each other, 

 ind at a good distance, as 50 pacesj and in the focus of one of them any words 

 be whispered, or a pocket watch be placed there, those whispers, or the ticking 

 of the watch, may be distinctly heard in the focus of the other mirror. 



///. ^n Extraordinary Case of Three Pins Swallowed by a Girl, and discharged 

 S'tt at her Shoulder. By Dr. Lysons, of Gloucester, p. 9. ■ 



' ''fileanor Kaylock, a strong girl, aged 22, was admitted a patient in the 

 tS^loucester infirmary. May 29, 1 766, for a pain in her side proceeding from 3 

 pins swallowed f of a year before. The occasion of the accident was thus: 

 being employed in the business of a kitchen, as she was scumming the pot, her 

 mouth being open, and 3 pins in it, she received a quantity of the vapour, 

 which obliged her to swallow, and the pins at the same time passed into the 

 oesophagus, where they remained for 8 weeks, notwithstanding various methods 

 were used for their removal ; but they were at last forced down by the whalebone 

 instrument used by surgeons for that purpose. While the pins were in her 

 throat, the parts became inflamed and svvoln, which occasioned a hoarseness, 

 attended with great pain, and difficulty of breathing; being also capable of re- 

 ceiving but very little nourishment, and that liquids, she was reduced to so weak 

 a state as not to be able to get out of her bed. After the pins were removed 

 she could swallow solids, and recovered strength sufiicient to go out again to ser- 

 vice in her former employment. She was hired as an under servant in a gen- 



